| Year | Rank | Number |
| 2011 | 11177 | 9 |
| 2009 | 15263 | 6 |
| 2008 | 17661 | 5 |
| 2007 | 10853 | 10 |
| 2006 | 10627 | 10 |
| 2005 | 10966 | 9 |
| 2004 | 14288 | 6 |
| 2003 | 15931 | 5 |
| 2002 | 11187 | 8 |
| 2001 | 9397 | 10 |
| 2000 | 11885 | 7 |
| 1999 | 9533 | 9 |
| 1998 | 8042 | 11 |
| 1997 | 10921 | 7 |
| 1996 | 11906 | 6 |
| 1995 | 8105 | 10 |
| 1993 | 10655 | 7 |
| 1992 | 13395 | 5 |
| 1990 | 13054 | 5 |
| 1989 | 8069 | 9 |
| 1988 | 11869 | 5 |
| 1987 | 9885 | 6 |
| 1977 | 7576 | 7 |
| 1976 | 6058 | 9 |
| 1974 | 6916 | 7 |